Upregulation of the lncRNA Meg3 induces autophagy to inhibit tumorigenesis and progression of epithelial ovarian carcinoma by regulating activity of ATG3

Regulating the regulators: long non-coding RNAs as autophagic controllers in chronic disease management

The increasing prevalence of chronic diseases and their associated morbidities demands a deeper understanding of underlying mechanism and causative factors, with the hope of developing novel therapeutic strategies. Autophagy, a conserved biological process, involves the degradation of damaged organelles or protein aggregates to maintain cellular homeostasis. Disruption of this crucial process leads to increased genomic instability, accumulation of reactive oxygen species (ROS), decreased mitochondrial functions, and suppression of ubiquitination, leading to overall decline in quality of intracellular components. Such deregulation has been implicated in a wide range of pathological conditions such as cancer, cardiovascular, inflammatory, and neurological disorders. This review explores the role of long non-coding RNAs (lncRNAs) as modulators of transcriptional and post-transcriptional gene expression, regulating diverse physiological process like proliferation, development, immunity, and metabolism. Moreover, lncRNAs are known to sequester autophagy related microRNAs by functioning as competing endogenous RNAs (ceRNAs), thereby regulating this vital process. In the present review, we delineate the multitiered regulation of lncRNAs in the autophagic dysfunction of various pathological diseases. Moreover, by highlighting recent findings on the modulation of lncRNAs in different stages of autophagy, and the emerging clinical landscape that recognizes lncRNAs in disease diagnosis and therapy, this review highlights the potential of lncRNAs as biomarkers and therapeutic targets in clinical settings of different stages of autophagic process by regulating ATG and its target genes. This focus on lncRNAs could lead to breakthroughs in personalized medicine, offering new avenues for diagnosis and treatment of complex diseases.

Noncoding RNAs: the crucial role of programmed cell death in osteoporosis

Osteoporosis is the most common skeletal disease characterized by an imbalance between bone resorption and bone remodeling. Osteoporosis can lead to bone loss and bone microstructural deterioration. This increases the risk of bone fragility and fracture, severely reducing patients' mobility and quality of life. However, the specific molecular mechanisms involved in the development of osteoporosis remain unclear. Increasing evidence suggests that multiple noncoding RNAs show differential expression in the osteoporosis state. Meanwhile, noncoding RNAs have been associated with an increased risk of osteoporosis and fracture. Noncoding RNAs are an important class of factors at the level of gene regulation and are mainly involved in cell proliferation, cell differentiation, and cell death. Programmed cell death is a genetically-regulated form of cell death involved in regulating the homeostasis of the internal environment. Noncoding RNA plays an important role in the programmed cell death process. The exploration of the noncoding RNA-programmed cell death axis has become an interesting area of research and has been shown to play a role in many diseases such as osteoporosis. In this review, we summarize the latest findings on the mechanism of noncoding RNA-mediated programmed cell death on bone homeostasis imbalance leading to osteoporosis. And we provide a deeper understanding of the role played by the noncoding RNA-programmed cell death axis at the gene regulatory level of osteoporosis. We hope to provide a unique opportunity to develop novel diagnostic and therapeutic approaches for osteoporosis.

The roles of long non-coding RNAs in ovarian cancer: from functions to therapeutic implications

Long non-coding RNAs (lncRNAs) are multifunctional and participate in a variety of biological processes and gene regulatory networks. The deregulation of lncRNAs has been extensively implicated in diverse human diseases, especially in cancers. Overwhelming evidence demonstrates that lncRNAs are essential to the pathophysiological processes of ovarian cancer (OC), acting as regulators involved in metastasis, cell death, chemoresistance, and tumor immunity. In this review, we illustrate the expanded functions of lncRNAs in the initiation and progression of OC and elaborate on the signaling pathways in which they pitch. Additionally, the potential clinical applications of lncRNAs as biomarkers in the diagnosis and treatment of OC were emphasized, cementing the bridge of communication between clinical practice and basic research.

The pivotal role of long non-coding RNAs as potential biomarkers and modulators of chemoresistance in ovarian cancer (OC)

Ovarian cancer (OC) is a fatal gynecological disease that is often diagnosed at later stages due to its asymptomatic nature and the absence of efficient early-stage biomarkers. Previous studies have identified genes with abnormal expression in OC that couldn't be explained by methylation or mutation, indicating alternative mechanisms of gene regulation. Recent advances in human transcriptome studies have led to research on non-coding RNAs (ncRNAs) as regulators of cancer gene expression. Long non-coding RNAs (lncRNAs), a class of ncRNAs with a length greater than 200 nucleotides, have been identified as crucial regulators of physiological processes and human diseases, including cancer. Dysregulated lncRNA expression has also been found to play a crucial role in ovarian carcinogenesis, indicating their potential as novel and non-invasive biomarkers for improving OC management. However, despite the discovery of several thousand lncRNAs, only one has been approved for clinical use as a biomarker in cancer, highlighting the importance of further research in this field. In addition to their potential as biomarkers, lncRNAs have been implicated in modulating chemoresistance, a major problem in OC. Several studies have identified altered lncRNA expression upon drug treatment, further emphasizing their potential to modulate chemoresistance. In this review, we highlight the characteristics of lncRNAs, their function, and their potential to serve as tumor markers in OC. We also discuss a few databases providing detailed information on lncRNAs in various cancer types. Despite the promising potential of lncRNAs, further research is necessary to fully understand their role in cancer and develop effective strategies to combat this devastating disease.

The role and function of autophagy through signaling and pathogenetic pathways and lncRNAs in ovarian cancer

Lysosomal-driven autophagy is a tightly controlled cellular catabolic process that breaks down and recycles broken or superfluous cell parts. It is involved in several illnesses, including cancer, and is essential in preserving cellular homeostasis. Autophagy prevents DNA mutation and cancer development by actively eliminating pro-oxidative mitochondria and protein aggregates from healthy cells. Oncosuppressor and oncogene gene mutations cause dysregulation of autophagy. Increased autophagy may offer cancer cells a pro-survival advantage when oxygen and nutrients are scarce and resistance to chemotherapy and radiation. This finding justifies the use of autophagy inhibitors in addition to anti-neoplastic treatments. Excessive autophagy levels can potentially kill cells. The diagnosis and treatment of ovarian cancer present many difficulties due to its complexity and heterogeneity. Understanding the role of autophagy, a cellular process involved in the breakdown and recycling of cellular components, in ovarian cancer has garnered increasing attention in recent years. Of particular note is the increasing amount of data indicating a close relationship between autophagy and ovarian cancer. Autophagy either promotes or restricts tumor growth in ovarian cancer. Dysregulation of autophagy signaling pathways in ovarian cancers can affect the development, metastasis, and response to tumor treatment. The precise mechanism underlying autophagy concerning ovarian cancer remains unclear, as does the role autophagy plays in ovarian carcinoma. In this review, we tried to encapsulate and evaluate current findings in investigating autophagy in ovarian cancer.

The role of ncRNA in the co-regulation of autophagy and exosome pathways during cancer progression

Since its discovery a few decades ago, autophagy has been recognized as a crucial signaling pathway, linked to the recycling of cellular components in nutrient stress. Autophagy is a two-way sword, playing a dual role in tumorigenesis. In this catabolic process, dysfunctional organelles, biomolecules, and misfolded proteins are sequestered in the autophagosome and sent to the lysosome for degradation. Alongside, there are cellular messengers called exosomes, which are released from cells and are known to communicate and regulate metabolism in recipient cells. Multivesicular bodies (MVB) act as the intricate link between autophagy and exosome pathways. The continuous crosstalk between the two pathways is coordinated and regulated by multiple players among which ncRNA is the emerging candidates. The exosomes carry varied cargo of which non-coding RNA exerts an immediate regulatory effect on recipient cells. ncRNA is known to exhibit dual behavior in both promoting and inhibiting tumor growth. There is increasing evidence for the involvement of ncRNAs' in the regulation of different hallmarks of cancer. Different ncRNAs are involved in the co-regulation of autophagy and exosome pathways and therefore represent a superior therapeutic approach to target cancer chemoresistance. Here, we will discuss the ncRNA involved in regulating autophagy, and exosomes pathways and its relevance in cancer therapeutics.

Role of autophagy and its regulation by noncoding RNAs in ovarian cancer

Autophagy is a self-digestion process by which misfolded proteins and damaged organelles in eukaryotic cells are degraded to maintain cellular homeostasis. This process is involved in the tumorigenesis, metastasis, and chemoresistance of various tumors such as ovarian cancer (OC). Noncoding RNAs (ncRNAs), mainly including microRNAs, long noncoding RNAs, and circular RNAs, have been extensively investigated in cancer research for their roles in the regulation of autophagy. Recent studies have shown that in OC cells, ncRNAs can modulate the formation of autophagosomes, which affect tumor progression and chemoresistance. An understanding of the role of autophagy in OC progression, treatment, and prognosis is important, and the identification of the regulatory roles of ncRNAs in autophagy leads to intervention strategies for OC therapy. This review summarizes the role of autophagy in OC and discusses the role of ncRNA-mediated autophagy in OC, as an understanding of these roles may contribute to the development of potential therapeutic strategies for this disease.

Lnc-ing epigenetic mechanisms with autophagy and cancer drug resistance

Long noncoding RNAs (lncRNAs) comprise a diverse class of RNA molecules that regulate various physiological processes and have been reported to be involved in several human pathologies ranging from neurodegenerative disease to cancer. Therapeutic resistance is a major hurdle for cancer treatment. Over the past decade, several studies has emerged on the role of lncRNAs in cancer drug resistance and many trials have been conducted employing them. LncRNAs also regulate different cell death pathways thereby maintaining a fine balance of cell survival and death. Autophagy is a complex cell-killing mechanism that has both cytoprotective and cytotoxic roles. Similarly, autophagy can lead to the induction of both chemosensitization and chemoresistance in cancer cells upon therapeutic intervention. Recently the role of lncRNAs in the regulation of autophagy has also surfaced. Thus, lncRNAs can be used in cancer therapeutics to alleviate the challenges of chemoresistance by targeting the autophagosomal axis. In this chapter, we discuss about the role of lncRNAs in autophagy-mediated cancer drug resistance and its implication in targeted cancer therapy.

Non-coding RNAs: The recently accentuated molecules in the regulation of cell autophagy for ovarian cancer pathogenesis and therapeutic response

Autophagy is a self-recycling and conserved process, in which the senescent cytoplasmic components are degraded in cells and then recycled to maintain homeostatic balance. Emerging evidence has suggested the involvement of autophagy in oncogenesis and progression of various cancers, such as ovarian cancer (OC). Meanwhile, the non-coding RNAs (ncRNAs) frequently regulate the mRNA transcription and other functional signaling pathways in cell autophagy, displaying promising roles in human cancer pathogenesis and therapeutic response. This article mainly reviews the cutting-edge research advances about the interactions between ncRNAs and autophagy in OC. This review not only summarizes the underlying mechanisms of dynamic ncRNA-autophagy association in OC, but also discusses their prognostic implications and therapeutic biomarkers. The aim of this review was to provide a more in-depth knowledge framework exploring the ncRNA-autophagy crosstalk and highlight the promising treatment strategies for OC patients.

Targeting Autophagy Using Long Non-Coding RNAs (LncRNAs): New Landscapes in the Arena of Cancer Therapeutics

Cancer has become a global health hazard accounting for 10 million deaths in the year 2020. Although different treatment approaches have increased patient overall survival, treatment for advanced stages still suffers from poor clinical outcomes. The ever-increasing prevalence of cancer has led to a reanalysis of cellular and molecular events in the hope to identify and develop a cure for this multigenic disease. Autophagy, an evolutionary conserved catabolic process, eliminates protein aggregates and damaged organelles to maintain cellular homeostasis. Accumulating evidence has implicated the deregulation of autophagic pathways to be associated with various hallmarks of cancer. Autophagy exhibits both tumor-promoting and suppressive effects based on the tumor stage and grades. Majorly, it maintains the cancer microenvironment homeostasis by promoting viability and nutrient recycling under hypoxic and nutrient-deprived conditions. Recent investigations have discovered long non-coding RNAs (lncRNAs) as master regulators of autophagic gene expression. lncRNAs, by sequestering autophagy-related microRNAs, have been known to modulate various hallmarks of cancer, such as survival, proliferation, EMT, migration, invasion, angiogenesis, and metastasis. This review delineates the mechanistic role of various lncRNAs involved in modulating autophagy and their related proteins in different cancers.

Long noncoding RNA RFPL1S-202 inhibits ovarian cancer progression by downregulating the IFN-β/STAT1 signaling

BACKGROUND

RFPL1S was first identified as one of the pseudogenes located in the intrachromosomal duplications within 22q12-13. Our previous study found that one of the predicted transcripts of lncRNA RFPL1S, ENST00000419368.1 (GRCh37/hg19), also named as RFPL1S-202 in Ensembl website, is significantly downregulated in the chemoresistant ovarian cancer cells. However, its function and underlying mechanism have not been studied.

METHODS

Quantitative Real-time PCR was used to analyze the expression. Cell Counting Kit-8, transwell, flow cytometry analysis and tail vein injected mouse model were used to test the function. RNA-sequencing, RNA pull down, western blot, ELISA and RNA-Binding Protein Immunoprecipitation were performed for studying the mechanism. 5' and 3' rapid amplification of complementary DNA ends were performed to analyze the full length of RFPL1S-202.

RESULTS

RFPL1S-202 is significantly downregulated in epithelial ovarian cancer tissues and cell lines. Gain- and loss-of-function study indicated that RFPL1S-202 could enhance cisplatin or paclitaxel in cytotoxicity, inhibit cell proliferation, invasion and migration of ovarian cancer cells in vitro, and inhibit the liver metastasis of ovarian cancer cells in vivo. Mechanistically, RFPL1S-202 could physically interact with DEAD-Box Helicase 3 X-linked (DDX3X) protein, and decrease the expression of p-STAT1 and the IFN inducible genes by increasing the m6A modification of IFNB1. RFPL1S-202 is a spliced and polyadenylated non-coding RNA with a full length of 1071 bp.

CONCLUSIONS

Our study suggested that the predicted lncRNA RFPL1S-202 exerts a tumor- suppressive function in oarian cancer chemoresistance and progression by interacting with DDX3X and down-regulating the IFN-β-STAT1 signaling pathway.

Non-coding RNA and autophagy: Finding novel ways to improve the diagnostic management of bladder cancer

Major fraction of the human genome is transcribed in to the RNA but is not translated in to any specific functional protein. These transcribed but not translated RNA molecules are called as non-coding RNA (ncRNA). There are thousands of different non-coding RNAs present inside the cells, each regulating different cellular pathway/pathways. Over the last few decades non-coding RNAs have been found to be involved in various diseases including cancer. Non-coding RNAs are reported to function both as tumor enhancer and/or tumor suppressor in almost each type of cancer. Urothelial carcinoma of the urinary bladder is the second most common urogenital malignancy in the world. Over the last few decades, non-coding RNAs were demonstrated to be linked with bladder cancer progression by modulating different signalling pathways and cellular processes such as autophagy, metastasis, drug resistance and tumor proliferation. Due to the heterogeneity of bladder cancer cells more in-depth molecular characterization is needed to identify new diagnostic and treatment options. This review emphasizes the current findings on non-coding RNAs and their relationship with various oncological processes such as autophagy, and their applicability to the pathophysiology of bladder cancer. This may offer an understanding of evolving non-coding RNA-targeted diagnostic tools and new therapeutic approaches for bladder cancer management in the future.

A review of current evidence about lncRNA MEG3: A tumor suppressor in multiple cancers

Long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3) is a lncRNA located at the DLK1-MEG3 site of human chromosome 14q32.3. The expression of MEG3 in various tumors is substantially lower than that in normal adjacent tissues, and deletion of MEG3 expression is involved in the occurrence of many tumors. The high expression of MEG3 could inhibit the occurrence and development of tumors through several mechanisms, which has become a research hotspot in recent years. As a member of tumor suppressor lncRNAs, MEG3 is expected to be a new target for tumor diagnosis and treatment. This review discusses the molecular mechanisms of MEG3 in different tumors and future challenges for the diagnosis and treatment of cancers through MEG3.

LncRNA MEG3: Potential stock for precision treatment of cardiovascular diseases

The prevalence and mortality rates of cardiovascular diseases are increasing, and new treatment strategies are urgently needed. From the perspective of basic pathogenesis, the occurrence and development of cardiovascular diseases are related to inflammation, apoptosis, fibrosis and autophagy of cardiomyocytes, endothelial cells and other related cells. The involvement of maternally expressed gene 3 (MEG3) in human disease processes has been increasingly reported. P53 and PI3K/Akt are important pathways by which MEG3 participates in regulating cell apoptosis. MEG3 directly or competitively binds with miRNA to participate in apoptosis, inflammation, oxidative stress, endoplasmic reticulum stress, EMT and other processes. LncRNA MEG3 is mainly involved in malignant tumors, metabolic diseases, immune system diseases, cardiovascular and cerebrovascular diseases, etc., LncRNA MEG3 has a variety of pathological effects in cardiomyocytes, fibroblasts and endothelial cells and has great clinical application potential in the prevention and treatment of AS, MIRI, hypertension and HF. This paper will review the research progress of MEG3 in the aspects of mechanism of action, other systemic diseases and cardiovascular diseases, and point out its great potential in the prevention and treatment of cardiovascular diseases. lncRNAs also play a role in endothelial cells. In addition, lncRNA MEG3 has shown biomarker value, prognostic value and therapeutic response measurement in tumor diseases. We boldly speculate that MEG3 will play a role in the emerging discipline of tumor heart disease.

Long Noncoding RNAs and Circular RNAs Regulate AKT and Its Effectors to Control Cell Functions of Cancer Cells

AKT serine-threonine kinase (AKT) and its effectors are essential for maintaining cell proliferation, apoptosis, autophagy, endoplasmic reticulum (ER) stress, mitochondrial morphogenesis (fission/fusion), ferroptosis, necroptosis, DNA damage response (damage and repair), senescence, and migration of cancer cells. Several lncRNAs and circRNAs also regulate the expression of these functions by numerous pathways. However, the impact on cell functions by lncRNAs and circRNAs regulating AKT and its effectors is poorly understood. This review provides comprehensive information about the relationship of lncRNAs and circRNAs with AKT on the cell functions of cancer cells. the roles of several lncRNAs and circRNAs acting on AKT effectors, such as FOXO, mTORC1/2, S6K1/2, 4EBP1, SREBP, and HIF are explored. To further validate the relationship between AKT, AKT effectors, lncRNAs, and circRNAs, more predicted AKT- and AKT effector-targeting lncRNAs and circRNAs were retrieved from the LncTarD and circBase databases. Consistently, using an in-depth literature survey, these AKT- and AKT effector-targeting database lncRNAs and circRNAs were related to cell functions. Therefore, some lncRNAs and circRNAs can regulate several cell functions through modulating AKT and AKT effectors. This review provides insights into a comprehensive network of AKT and AKT effectors connecting to lncRNAs and circRNAs in the regulation of cancer cell functions.

Exosomal long noncoding RNAs - the lead thespian behind the regulation, cause and cure of autophagy-related diseases

Recent advances in exosome biology have revealed significant roles of exosome and their contents in intercellular communication. Among various exosomal content, long non-coding RNAs (lncRNAs), which have a large size (˃ 200 nt) and lack protein coding potential, are known to play key roles in intercellular communication and novel biomarkers of various metabolic disorders. Moreover, long non-coding RNAs are often involved in the regulation of various cellular processes such as autophagy, apoptosis, cell proliferation. On the other hand, autophagy is the central regulating point that controls the various metabolic functions of the body. This process is known to prevent diseases and promote longevity. Therefore, the present review discusses the relationship between diseases and autophagy, and also look into the biological functions of exosome-associated lncRNAs in regulating autophagy. Furthermore, this review will summarize some of the studies that provide novel insights into the pathogenesis of autophagy-related diseases followed by the non-canonical roles played by autophagy and related proteins in the development of exosome biogenesis.

PITPNA-AS1/miR-98-5p to Mediate the Cisplatin Resistance of Gastric Cancer

Gastric cancer (GC) is the most deadly gastrointestinal malignancy with high incidence and mortality. Although, molecular mechanisms which drive gastric cancer progression are extensively investigated, the roles of long noncoding RNA (lncRNA) in gastric cancer growth and drug sensitivity remain unclear. Platinum is a mainstay to treat gastric cancer, and platinum resistance always leads to the local recurrence of gastric cancer. Therefore, it is important to identify biomarkers or therapeutic targets to sensitize gastric cancer to platinum. In this study, we employ noncoding RNA sequencing and found that lncRNA PITPNA-AS1 is overexpressed in gastric cancer tissues and associated with poor survival of gastric cancer patients. Kockdown of PITPNA-AS1 in gastric cancer cells significantly inhibited cell growth and triggered apoptotic cell death in gastric cancer cells. Also, cisplatin treatment could decrease PITPNA-AS1 levels in gastric cancer cells through inhibiting H3K27ac. Besides, PITPNA-AS1 is elevated in cisplatin-resistant gastric cancer cells and tissues, PITPNA-AS1 knockdown could sensitize gastric cancer cells to cisplatin treatment. Furthermore, we identified that PITPNA-AS1 directly interacts and inhibits miR-98-5p. Therefore, PITPNA-AS1 could be served as a potential biomarkers and curative therapeutic targets for gastric cancer progression.

Exploring the role of non-coding RNAs in autophagy

As a self-degradative mechanism, macroautophagy/autophagy has a role in the maintenance of energy homeostasis during critical periods in the development of cells. It also controls cellular damage through the eradication of damaged proteins and organelles. This process is accomplished by tens of ATG (autophagy-related) proteins. Recent studies have shown the involvement of non-coding RNAs in the regulation of autophagy. These transcripts mostly modulate the expression of ATG genes. Both long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been shown to modulate the autophagy mechanism. Levels of several lncRNAs and miRNAs are altered in this process. In the present review, we discuss the role of lncRNAs and miRNAs in the regulation of autophagy in diverse contexts such as cancer, deep vein thrombosis, spinal cord injury, diabetes and its complications, acute myocardial infarction, osteoarthritis, pre-eclampsia and epilepsy.Abbreviations: AMI: acute myocardial infarction; ATG: autophagy-related; lncRNA: long non-coding RNA; miRNA: microRNA.

Long non-coding RNA TSPEAR Antisense RNA 2 is downregulated in rheumatoid arthritis and inhibits the apoptosis of fibroblast-like synoviocytes by downregulating microRNA-212-3p (miR-212-3p)

Long non-coding RNA (lncRNA) TSPEAR-AS2 (TSPEAR Antisense RNA 2) participates in many human diseases, while its roles in rheumatoid arthritis (RA) are unknown. Plasma expression levels of TSPEAR-AS2 and microRNA (miR)-212-3p in both RA patients and healthy controls were measured by RT-qPCR. Diagnostic potentials of plasma TSPEAR-AS2 and miR-212-3p were assessed by ROC curve analysis. Normalized expression levels of TSPEAR-AS2 and miR-212-3p were subjected to Pearson’s correlation coefficient to evaluate their corrections. TSPEAR-AS2 was significantly downregulated in RA patients, while plasma expression levels of miR-212-3p were significantly increased in RA patients. The expression of TSPEAR-AS2 and miR-212-3p showed promising diagnostic value for RA. Plasma expression levels of TSPEAR-AS2 and miR-212-3p were significantly and inversely correlated in RA patients but not in healthy controls. Besides, overexpression of TSPEAR-AS2 decreased the apoptosis of RA HFLSs, while miR-212-3p increased cell apoptosis. In addition, miR-212-3p attenuated the effects of overexpression of TSPEAR-AS2. Overexpression of TSPEAR-AS2 decreased the expression levels of miR-212-3p in HFLS, while overexpression of miR-212-3p did not affect the expression of TSPEAR-AS2. In conclusion, TSPEAR-AS2 is downregulated in RA and its overexpression can decrease the apoptosis of RA HFLSs by downregulating miR-212-3p.

Parkinson's Disease Is Associated With Dysregulation of Circulatory Levels of lncRNAs

Long non-coding RNAs (lncRNAs) have been recently reported to be involved in the pathoetiology of Parkinson’s disease (PD). Circulatory levels of lncRNAs might be used as markers for PD. In the present work, we measured expression levels of HULC, PVT1, MEG3, SPRY4-IT1, LINC-ROR and DSCAM-AS1 lncRNAs in the circulation of patients with PD versus healthy controls. Expression of HULC was lower in total patients compared with total controls (Expression ratio (ER)=0.19, adjusted P value<0.0001) as well as in female patients compared with female controls (ER=0.071, adjusted P value=0.0004). Expression of PVT1 was lower in total patients compared with total controls (ER=0.55, adjusted P value=0.0124). Expression of DSCAM-AS1 was higher in total patients compared with total controls (ER=5.67, P value=0.0029) and in male patients compared with male controls (ER=9.526, adjusted P value=0.0024). Expression of SPRY4-IT was higher in total patients compared with total controls (ER=2.64, adjusted P value<0.02) and in male patients compared with male controls (ER=3.43, P value<0.03). Expression of LINC-ROR was higher in total patients compared with total controls (ER=10.36, adjusted P value<0.0001) and in both male and female patients compared with sex-matched controls (ER=4.57, adjusted P value=0.03 and ER=23.47, adjusted P value=0.0019, respectively). Finally, expression of MEG3 was higher in total patients compared with total controls (ER=13.94, adjusted P value<0.0001) and in both male and female patients compared with sex-matched controls (ER=8.60, adjusted P value<0.004 and ER=22.58, adjusted P value<0.0085, respectively). ROC curve analysis revealed that MEG3 and LINC-ROR have diagnostic power of 0.77 and 0.73, respectively. Other lncRNAs had AUC values less than 0.7. Expression of none of lncRNAs was correlated with age of patients, disease duration, disease stage, MMSE or UPDRS. The current study provides further evidence for dysregulation of lncRNAs in the circulation of PD patients.

The Role of Long Non-Coding RNAs (lncRNAs) in Female Oriented Cancers

Recent advances in molecular biology have discovered the mysterious role of long non-coding RNAs (lncRNAs) as potential biomarkers for cancer diagnosis and targets for advanced cancer therapy. Studies have shown that lncRNAs take part in the incidence and development of cancers in humans. However, previously they were considered as mere RNA noise or transcription byproducts lacking any biological function. In this article, we present a summary of the progress on ascertaining the biological functions of five lncRNAs (HOTAIR, NEAT1, H19, MALAT1, and MEG3) in female-oriented cancers, including breast and gynecological cancers, with the perspective of carcinogenesis, cancer proliferation, and metastasis. We provide the current state of knowledge from the past five years of the literature to discuss the clinical importance of such lncRNAs as therapeutic targets or early diagnostic biomarkers. We reviewed the consequences, either oncogenic or tumor-suppressing features, of their aberrant expression in female-oriented cancers. We tried to explain the established mechanism by which they regulate cancer proliferation and metastasis by competing with miRNAs and other mechanisms involved via regulating genes and signaling pathways. In addition, we revealed the association between stated lncRNAs and chemo-resistance or radio-resistance and their potential clinical applications and future perspectives.

Autophagy and gastrointestinal cancers: the behind the scenes role of long non-coding RNAs in initiation, progression, and treatment resistance

Gastrointestinal (GI) cancers comprise a heterogeneous group of complex disorders that affect different organs, including esophagus, stomach, gallbladder, liver, biliary tract, pancreas, small intestine, colon, rectum, and anus. Recently, an explosion in nucleic acid-based technologies has led to the discovery of long non-coding RNAs (lncRNAs) that have been found to possess unique regulatory functions. This class of RNAs is >200 nucleotides in length, and is characterized by their lack of protein coding. LncRNAs exert regulatory effects in GI cancer development by affecting different functions such as the proliferation and metastasis of cancer cells, apoptosis, glycolysis and angiogenesis. Over the past few decades, considerable evidence has revealed the important role of autophagy in both GI cancer progression and suppression. In addition, recent studies have confirmed a significant correlation between lncRNAs and the regulation of autophagy. In this review, we summarize how lncRNAs play a behind the scenes role in the pathogenesis of GI cancers through regulation of autophagy.

Screening and analysis for autophagyrelated lncRNA in fibroblastlike synoviocytes from patients with rheumatoid arthritis

OBJECTIVES

Long non-coding RNA (lncRNA) has become a key epigenetic regulator that regulates gene expression and affects a variety of biological processes. LncRNA plays an important role in the occurrence and development of rheumatoid arthritis (RA). The study on lncRNA in peripheral blood cells of RA patients has been reported. However, there is no study on autophagy regulation by lncRNA in RA patients. This study aims to provide a new direction for the diagnosis and treatment of RA via screening the changes of lncRNAs in RA fibroblast-like synoviocytes (RA-FLSs) before and after autophagy and finding the key lncRNAs targeting RA-FLSs autophagy.

METHODS

Synovial tissues of 6 RA patients after knee and hip joint surgery were obtained, and RA-FLSs were cultured to the 5th generation for further experiments (tissue culture method). After treatment with mTOR inhibitor PP242, the expression of LC3-II was detected by Western blotting. Total RNAs of 3 cases of RA-FLSs before and after treatment with mTOR inhibitor PP242 were extracted by TRIzol and screened by Agilent Human ceRNA Microarray 2019 (4×180 K, design ID: 086188) chip. The lncRNAs with significantly changed expression levels were selected (difference multiple≥2.0, P<0.05). Bioinformatics technology was used to analyze the gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway of the differentially expressed lncRNAs, and to explore the possible role of differentially expressed lncRNAs in the pathogenesis of RA. Subsequently, ENST00000584721.1 and ENST00000615939.1 were identified in all the 6 samples of RA-FLSs using real-time RT-PCR, which were selected by previous chip screen combined with GO enrichment analysis and KEGG analysis.

RESULTS

RA-FLSs were successfully isolated and cultured from the synovial tissues of the patient's knee or hip joint. After 6 RA-FLSs were treated with PP242, the expression level of autophagy marker protein LC3-II was increased (P<0.05). PP242 induced autophagy in RA-FLSs. LncRNA sequencing analysis showed that a total of 591 lncRNAs were significantly changed, of which 428 were up-regulated and 163 were down-regulated.Go analysis showed that these differentially expressed lncRNAs were associated with negative regulation of Th17 function, T cell related cytokines production, and TGF-β receptor signaling pathway, as well as IL-6 receptor complex formation and type I TGF-β receptor binding. KEGG analysis showed that autophagy pathway, TGF-β, TNF-α, IL-17 signaling pathway, and Th17, Th1, Th2, osteoclast differentiation pathway were the most abundant signal pathways of differentially expressed lncRNAs during autophagy. The expression of ENST00000584721.1 was up-regulated (P<0.05) and the expression ofENST00000615939.1 was down-regulated (P<0.05) in RA-FLSs undergoing autophagy, by using real-time RT-PCR validation which was in consistent with the microarray results. The reliability of microarray screening differential genes was confirmed. GO analysis showed that ENST00000584721.1 and ENST00000615939.1 were related to ribosome transport and autophagy assembly, respectively. KEGG analysis showed that ENST00000584721.1 was related to mitogen-activated protein kinase (MAPK) signaling pathway, and ENST00000615939.1 was related to FoxO signaling pathway.

CONCLUSIONS

Differentially expressed lncRNAs in RA-FLSs have been identified with microarray analysis. In RA, differential expression of lncRNAs is involved in the autophagy of RA-FLSs. The underlying mechanisms based on bioinformatics analysis include regulating the secretion of cytokines, such as IL-6, TGF-β, TNF-α and IL-17, participating in the immune cell differentiation, such as Th17, Th1, Th2 cells and osteoclasts, as well as regulating the autophagy pathway, MAPK, FoxO, and other signaling pathways. It has been verified that the expression of ENST0000584721.1 is up-regulated and ENST0000615939.1 is down-regulated after autophagy of RA FLSs, which provides a good experimental basis for further study on the mechanism of lncRNA in RA-FLSs autophagy.

Lnc-MEG3 inhibits invasion, migration, and epithelial- mesenchymal transition of nasopharyngeal carcinoma cells by regulating sequestosome 1

BACKGROUND

Long non-coding RNAs regulate malignant behaviors of nasopharyngeal carcinoma (NPC). We aim to investigate the roles and mechanisms of long non-coding RNA maternally expressed gene 3 (lnc-MEG3) in NPC.

METHODS

The expression levels of lnc-MEG3 and sequestosome 1 (SQSTM1) in NPC tissues and cell lines were detected by quantitative real-time polymerase chain reaction (qRT-PCR). Cell invasion and migration abilities were evaluated using transwell and wound healing assays, respectively.

RESULTS

Downregulated lnc-MEG3 expression and upregulated SQSTM1 expression were found in NPC tissues and cells. Overexpression of lnc-MEG3 inhibited invasion, migration, and epithelial-mesenchymal transition in NPC cells. Overexpression of lnc-MEG3 reduced the expression level of SQSTM1, and SQSTM1 expression was inversely correlated with lnc-MEG3 level in NPC tissues. Besides, overexpression of SQSTM1 reversed the effects of lnc-MEG3 overexpression. Moreover, knockdown of lnc-MEG3 enhanced NPC progression while its effects were eased by SQSTM1 silence.

CONCLUSION

Lnc-MEG3 inhibits malignant behaviors by regulating SQSTM1 expression. It may serve as a therapeutic target to treat NPC.

(In)Distinctive Role of Long Non-Coding RNAs in Common and Rare Ovarian Cancers

Rare ovarian cancers (ROCs) are OCs with an annual incidence of fewer than 6 cases per 100,000 women. They affect women of all ages, but due to their low incidence and the potential clinical inexperience in management, there can be a delay in diagnosis, leading to a poor prognosis. The underlying causes for these tumors are varied, but generally, the tumors arise due to alterations in gene/protein expression in cellular processes that regulate normal proliferation and its checkpoints. Dysregulation of the cellular processes that lead to cancer includes gene mutations, epimutations, non-coding RNA (ncRNA) regulation, posttranscriptional and posttranslational modifications. Long non-coding RNA (lncRNA) are defined as transcribed RNA molecules, more than 200 nucleotides in length which are not translated into proteins. They regulate gene expression through several mechanisms and therefore add another level of complexity to the regulatory mechanisms affecting tumor development. Since few studies have been performed on ROCs, in this review we summarize the mechanisms of action of lncRNA in OC, with an emphasis on ROCs.

Long non-coding RNAs: A view to kill ovarian cancer

An emerging role of long non-coding RNAs (lncRNAs) in tumor progression has been revealed in the last decade. Through interactions with nucleic acids and proteins, lncRNAs could act as enhancers, scaffolds or decoys for a number of oncoproteins and tumor suppressors. The aberrant lncRNA expression or mutations are often associated with changes in a variety of cellular processes, including proliferation, stress response and cell death. Here, we will focus on the tumor-associated lncRNAs in ovarian cancer according to their contribution to cancer hallmarks, such as intense proliferation, cell death resistance, altered energy metabolism, invasion and metastasis, and immune evasion. Moreover, the potential clinical implications of lncRNAs and their significance for the diagnosis, prognosis and therapy of ovarian cancer will be discussed.

Non-Coding RNAs as Biomarkers of Tumor Progression and Metastatic Spread in Epithelial Ovarian Cancer

Simple Summary

Despite advances in cancer research in recent years, efficient predictive biomarkers of tumor progression and metastatic spread for ovarian cancer are still missing. Therefore, we critically address recent findings in the field of non-coding RNAs (microRNAs and long non-coding RNAs) and DNA methylation in ovarian cancer patients as promising novel biomarkers of ovarian cancer progression.

Abstract

Ovarian cancer is one of the most common causes of death among gynecological malignancies. Molecular changes occurring in the primary tumor lead to metastatic spread into the peritoneum and the formation of distant metastases. Identification of these changes helps to reveal the nature of metastases development and decipher early biomarkers of prognosis and disease progression. Comparing differences in gene expression profiles between primary tumors and metastases, together with disclosing their epigenetic regulation, provides interesting associations with progression and metastasizing. Regulatory elements from the non-coding RNA families such as microRNAs and long non-coding RNAs seem to participate in these processes and represent potential molecular biomarkers of patient prognosis. Progress in therapy individualization and its proper targeting also rely upon a better understanding of interactions among the above-listed factors. This review aims to summarize currently available findings of microRNAs and long non-coding RNAs linked with tumor progression and metastatic process in ovarian cancer. These biomolecules provide promising tools for monitoring the patient’s response to treatment, and further they serve as potential therapeutic targets of this deadly disease.

Vitamin D receptor upregulates lncRNA TOPORS-AS1 which inhibits the Wnt/β-catenin pathway and associates with favorable prognosis of ovarian cancer

Long non-coding RNAs (lncRNAs) have important biological functions, but their involvement in ovarian cancer remains elusive. We analyzed high-throughput data to identify lncRNAs associated with ovarian cancer outcomes. Our search led to the discovery of lncRNA TOPORS Antisense RNA 1 (TOPORS-AS1). Patients with high TOPORS-AS1 expression had favorable overall survival compared to low expression. This association was replicated in our study and confirmed by meta-analysis. In vitro experiments demonstrated that overexpressing TOPORS-AS1 in ovarian cancer cells suppressed cell proliferation and inhibited aggressive cell behaviors, including migration, invasion, and colony formation. Analysis of tumor cell transcriptomes indicated TOPORS-AS1′s influence on the Wnt/β-catenin signaling. Additional experiments revealed that TOPORS-AS1 increased the phosphorylation of β-catenin and suppressed the expression of CTNNB1, disrupting the Wnt/β-catenin pathway. Our experiments further discovered that vitamin D receptor (VDR) upregulated TOPORS-AS1 expression and that inhibition of β-catenin by TOPORS-AS1 required a RNA binding protein, hnRNPA2B1 (heterogeneous nuclear ribonucleoprotein A2B1). Taken together, these findings suggest that TOPORS-AS1 may behave like a tumor suppressor in ovarian cancer through interrupting the Wnt/β-catenin signaling and that VDR upregulates the expression of TOPORS-AS1. Assessing TOPORS-AS1 expression in ovarian cancer may help predict disease prognosis and develop treatment strategy

Prognostic value of an autophagy-related long-noncoding-RNA signature for endometrial cancer

This study retrieved the transcriptome profiling data of 552 endometrial cancer (EC) patients from the TCGA (The Cancer Genome Atlas) database, and identified 1297 lncRNAs (long noncoding RNAs) related to autophagy genes using Pearson correlation analysis. Univariate Cox regression analysis of the training data set revealed that 14 autophagy-related lncRNAs had significantly prognostic value for endometrial cancer (P < 0.01). Multivariate Cox regression analysis of these autophagy-related lncRNAs established the following autophagy-related lncRNA prognosis signature for endometrial cancer: PI = (0.255 × AC005229.4 expression) + (0.405 × BX322234.1 expression) + (0.169 × FIRRE expression value) + (-0.122 × RAB11B-AS1 expression) + (-0.338 × AC003102.1 expression). This signature was validated in both the testing data set and the entire data set. The areas under the receiver operating characteristics curves for the 1-, 3-, and 5-year overall survival rates in the entire data set were 0.772, 0.733, and 0.714, respectively. In addition, a gene set enrichment analysis confirmed that cancer-related and autophagy-related pathways were significantly up-regulated in the high-risk group. In summary, this study has demonstrated that a signature comprising five autophagy-related lncRNAs has potential as an independent prognostic indicator of endometrial cancer, and also that these lncRNAs may play a key role in the development of endometrial cancer.

Long non-coding RNA MEG3 promotes autophagy and apoptosis of nasopharyngeal carcinoma cells via PTEN up-regulation by binding to microRNA-21

Long non-coding RNAs (lncRNAs) have been highlighted as attractive markers for diagnosis and prognosis as well as new therapeutic targets in multiple cancers, including nasopharyngeal carcinoma (NPC). Here, we attempted to investigate the underlying regulatory role of the lncRNA maternally expressed gene 3 (MEG3) in NPC development. As determined by RT-qPCR, MEG3 expression was down-regulated in NPC cells. Online RNA crosstalk analysis predicted the binding of miR-21 to MEG3 and PTEN, respectively. MEG3 was validated to bind to miR-21 while PTEN was identified as a target of miR-21 by dual-luciferase reporter gene assay. Exogenous transfection was done to change the levels of MEG3, miR-21 and PTEN in HK-1 cells to investigate their effects on the autophagy and apoptosis of NPC cells. The results suggested that MEG3 overexpression in HK-1 cells up-regulated PTEN and down-regulated miR-21, by which MEG3 further inhibited autophagy and apoptosis ability of NPC cells. The tumour formation ability was tested after injecting the HK-1 cells into nude, mice and tumour growth was monitored. Consistently, MEG3 overexpression inhibited the tumour formation in vivo. Collectively, MEG3 promotes the autophagy and apoptosis of NPC cells via enhancing PTEN expression by binding to miR-21.

Regulatory effects of noncoding RNAs on the interplay of oxidative stress and autophagy in cancer malignancy and therapy

Noncoding RNAs (ncRNAs) regulation of various diseases including cancer has been extensively studied. Reactive oxidative species (ROS) elevated by oxidative stress are associated with cancer progression and drug resistance, while autophagy serves as an ROS scavenger in cancer cells. However, the regulatory effects of ncRNAs on autophagy and ROS in various cancer cells remains complex. Here, we explore how currently investigated ncRNAs, mainly miRNAs and lncRNAs, are involved in ROS production through modulating antioxidant genes. The regulatory effects of miRNAs and lncRNAs on autophagy-related (ATG) proteins to control autophagy activity in cancer cells are discussed. Moreover, differential expression of ncRNAs in tumor and normal tissues of cancer patients are further analyzed using The Cancer Genome Atlas (TCGA) database. This review hypothesizes links between ATG genes- or antioxidant genes-modulated ncRNAs and ROS production, which might result in tumorigenesis, malignancy, and cancer recurrence. A better understanding of the regulation of ROS and autophagy by ncRNAs might advance the use of ncRNAs as diagnostic and prognostic markers as well as therapeutic targets in cancer therapy.

Autophagy Takes Center Stage as a Possible Cancer Hallmark

Cancer remains one of the leading causes of death worldwide, despite significant advances in cancer research and improvements in anticancer therapies. One of the major obstacles to curing cancer is the difficulty of achieving the complete annihilation of resistant cancer cells. The resistance of cancer cells may not only be due to intrinsic factors or factors acquired during the evolution of the tumor but may also be caused by chemotherapeutic treatment failure. Conversely, autophagy is a conserved cellular process in which intracellular components, such as damaged organelles, aggregated or misfolded proteins and macromolecules, are degraded or recycled to maintain cellular homeostasis. Importantly, autophagy is an essential mechanism that plays a key role in tumor initiation and progression. Depending on the cellular context and microenvironmental conditions, autophagy acts as a double-edged sword, playing a role in inducing apoptosis or promoting cell survival. In this review, we propose several scenarios in which autophagy could contribute to cell survival or cell death. Moreover, a special focus on novel promising targets and therapeutic strategies based on autophagic resistant cells is presented.

Analysis of diagnostic and prognostic value of lncRNA MEG3 in cervical cancer

The present study aimed to explore the diagnostic and prognostic value of lncRNA maternally expressed 3 (MEG3) in cervical cancer. Eighty-four patients with cervical cancer from February 2013 to March 2014 were enrolled in the observation group (OG), and another 58 female subjects who underwent physical examination at Huangshi Central Hospital were enrolled as the control group (CG). The serum MEG3 expression of patients in the two groups was detected by RT-qPCR, and the ability of MEG3 to aid in the diagnosis of cervical cancer, lymph node metastasis and FIGO staging, as well as to predict mortality was evaluated by ROC curve. In addition, the patients in the OG were divided into high- and low-expression groups according to the median value of MEG3. Kaplan Meier was employed to analyze the survival status, and Cox regression to analyze the independent prognostic factors of cervical cancer patients. The results of the present study revealed that the serum MEG3 expression in the OG was significantly lower than that of the CG (P<0.05). The area under the curve (AUC) of MEG3 in diagnosing cervical cancer was 0.844, the AUC in predicting mortality was 0.858, while that in diagnosing lymph node transfer was 0.707, and that in diagnosing FIGO staging was 0.791. The 5-year survival rate of the high-expression group was higher than that of the low-expression group (P=0.020). Multivariate analysis indicated that MEG3 (HR, 0.173; 95 CI%, 0.028-0.919), lymph node metastasis (HR, 2.259; 95 CI%, 1.004-5.025) and FIGO staging (HR, 0.008; 95 CI%, 1.453-6.248) were independent prognostic factors for cervical cancer patients. Collectively, lncRNA MEG3 may be a diagnostic marker and prognostic indicator for cervical cancer, and has a certain diagnostic value for lymph node metastasis and FIGO staging. Lymph node metastasis, FIGO stage III and IV, and low MEG3 levels were revealed to be independent prognostic factors for cervical cancer patients.

LncRNA MEG3 rs3087918 was associated with a decreased breast cancer risk in a Chinese population: a case-control study

Background

LncRNA MEG3 expressed abnormally in various cancers including breast cancer, but no studies reported the correlation between MEG3 SNPs and breast cancer susceptibility among Chinese women.

Methods

This study is aimed to explore the association between three SNPs of MEG3 (rs3087918, rs7158663, rs11160608) and breast cancer. The study is a population-based case-control study including 434 breast cancer patients and 700 healthy controls. Genotyping was performed using Sequenom MassArray technique. Function prediction of rs3087918 were based on RNAfold and lncRNASNP2 databases.

Results

Pooled analysis indicated that rs3087918 was related to a decreased risk of breast cancer [GG vs. TT: OR (95%) = 0.67(0.45–0.99), P = 0.042; GG vs. TT + TG: OR (95%) = 0.69(0.48–0.99), P = 0.046], especially for women aged <=49 [GG vs. TT: OR (95%) = 0.40(0.22–0.73), P = 0.02]. Comparison between case groups showed genotype GG and TG/GG of rs3087918 were associated with her-2 receptor expression [GG vs. TT: OR (95%) = 2.37(1.24–4.63), P = 0.010; TG + GG vs. TT: OR (95%) = 1.50(1.01–2.24), P = 0.045]. We didn’t find statistical significance for rs11160608, rs7158663 and breast cancer. Structure prediction based on RNAfold found rs3087918 may influence the secondary structure of MEG3. The results based on lncRNASNP2 indicated that rs3087918 may gain the targets of hsa-miR-1203 to MEG3, while loss the target of hsa-miR-139-3p and hsa-miR-5091 to MEG3.

Conclusions

MEG3 rs3087918 was associated with a decreased risk of breast cancer. MEG3 haplotype TCG may increase the risk of breast cancer.

The role of epigenetics and non-coding RNAs in autophagy: A new perspective for thorough understanding

Autophagy is a major self-degradative intracellular process required for the maintenance of homeostasis and promotion of survival in response to starvation. It plays critical roles in a large variety of physiological and pathological processes. On the other hand, aberrant regulation of autophagy can lead to various cancers and neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, and Crohn's disease. Emerging evidence strongly supports that epigenetic signatures, related non-coding RNA profiles, and their cross-talking are significantly associated with the control of autophagic responses. Therefore, it may be helpful and promising to manage autophagic processes by finding valuable markers and therapeutic approaches. Although there is a great deal of information on the components of autophagy in the cytoplasm, the molecular basis of the epigenetic regulation of autophagy has not been completely elucidated. In this review, we highlight recent research on epigenetic changes through the expression of autophagy-related genes (ATGs), which regulate autophagy, DNA methylation, histone modifications as well as non-coding RNAs, including long non-coding RNAs (lncRNAs), microRNAs (miRNAs) and their relationship with human diseases, that play key roles in causing autophagy-related diseases.

Identification of aberrantly expressed long non-coding RNAs in ovarian high-grade serous carcinoma cells

PURPOSE

To identify the aberrantly expressed long non-coding RNAs (lncRNAs) in ovarian high-grade serous carcinoma (HGSC).

METHODS

Total RNA was isolated in HGSC cell lines, ovarian surface epithelial cells, and normal ovaries. Aberrantly expressed lncRNAs in HGSC were identified by PCR array, which analyzes 84 kinds of lncRNAs. To infer their functions, HGSC cell lines with different levels of expression of the identified lncRNAs were established, and then, activities of proliferation, migration, and apoptosis were examined. Expression levels of the identified lncRNAs were also examined in multiple ovarian HGSC tissues.

RESULTS

Ten aberrantly expressed lncRNAs, six upregulated and four downregulated, were identified in the HGSC cell lines. The authors established four HGSC cell lines: in two of the cell lines, one of the upregulated lncRNAs was knocked down, and in two other cell lines, one of the downregulated lncRNAs (MEG3 and POU5F1P5) was overexpressed. Migration activities were inhibited in the HGSC cell lines overexpressing MEG3 or POU5F1P5 while there were no differences in proliferation and apoptosis between the established and control cell lines. The four lncRNAs downregulated in the HGSC cell lines were also observed to be downregulated in ovarian HGSC tissues.

CONCLUSION

The authors identified four downregulated lncRNAs in ovarian HGSC.

Long noncoding RNA PITPNA-AS1 promotes cervical cancer progression through regulating the cell cycle and apoptosis by targeting the miR-876-5p/c-MET axis

Cervical cancer is a common tumor type and a leading cause of tumor death among female in the world. However, the molecular mechanisms revealing the cervical cancer progression have not been fully investigated. Long noncoding RNA (LncRNA) PITPNA-AS1 is a newly found lncRNA, showing the promoting role in tumor growth. But its effects on cervical cancer development still remain unknown. In the study, we found that PITPNA-AS1 was markedly increased in human cervical cancer tissues and cell lines. PITPNA-AS1 over-expression elevated the proliferation of cervical cancer cells, whereas PITPNA-AS1 knockdown reduced the cell proliferation. Moreover, PITPNA-AS1 knockdown markedly accelerated the G0/G1 and reduced the G2/M phase transitions through decreasing the cyclin-dependent kinase (CDK)-2/4/6 and CyclinD1 expression levels. In addition, apoptosis was significantly induced by PITPNA-AS1 knockdown in cervical cancer cells. Importantly, PITPNA-AS1 was identified as the sponge of miR-876-5p, and a negative correlation was detected between PITPNA-AS1 and miR-876-5p in cervical cancer samples. Moreover, tyrosine-protein kinase MET (c-MET) was identified to be a down-streaming target gene of miR-876-5p in cervical cancer cells. PITPNA-AS1 meditated the effects of c-MET on the proliferation, apoptosis and cell cycle in cervical cancer cells by adsorbing miR-876-5p. In summary, targeting the PITPNA-AS1-associated signaling could be a therapeutic strategy for the treatment of cervical cancer.

Mechanisms of Long Non-Coding RNAs in Cancers and Their Dynamic Regulations

Long non-coding RNA (lncRNA), which is a kind of noncoding RNA, is generally characterized as being more than 200 nucleotide transcripts in length. LncRNAs exhibit many biological activities, including, but not limited to, cancer development. In this review, a search of the PubMed database was performed to identify relevant studies published in English. The term "lncRNA or long non-coding RNA" was combined with a range of search terms related to the core focus of the review: mechanism, structure, regulation, and cancer. The eligibility of the retrieved studies was mainly based on the abstract. The decision as to whether or not the study was included in this review was made after a careful assessment of its content. The reference lists were also checked to identify any other study that could be relevant to this review. We first summarized the molecular mechanisms of lncRNAs in tumorigenesis, including competing endogenous RNA (ceRNA) mechanisms, epigenetic regulation, decoy and scaffold mechanisms, mRNA and protein stability regulation, transcriptional and translational regulation, miRNA processing regulation, and the architectural role of lncRNAs, which will help a broad audience better understand how lncRNAs work in cancer. Second, we introduced recent studies to elucidate the structure of lncRNAs, as there is a link between lncRNA structure and function and visualizing the architectural domains of lncRNAs is vital to understanding their function. Third, we explored emerging evidence for regulators of lncRNA expression, lncRNA turnover, and lncRNA modifications (including 5-methylcytidine, N6-methyladenosine, and adenosine to inosine editing), highlighting the dynamics of lncRNAs. Finally, we used autophagy in cancer as an example to interpret the diverse mechanisms of lncRNAs and introduced clinical trials of lncRNA-based cancer therapies.

Expression of long noncoding RNAs in cancer-associated fibroblasts linked to patient survival in ovarian cancer

Cancer-associated fibroblasts (CAFs) are the most abundant cell type in the tumor microenvironment and are responsible for producing the desmoplastic reaction that is a poor prognostic factor in ovarian cancer. Long non-coding RNAs (lncRNAs) have been shown to play important roles in cancer. However, very little is known about the role of lncRNAs in the tumor microenvironment. We aimed to identify lncRNAs expressed in ovarian CAFs that were associated with patient survival and used computational approaches to predict their function. Increased expression of 9 lncRNAs and decreased expression of 1 lncRNA in ovarian CAFs were found to be associated with poorer overall survival. A "guilt-by-association" approach was used to predict the function of these lncRNAs. In particular, MIR155HG was predicted to play a role in immune response. Further investigation revealed high MIR155HG expression to be associated with higher infiltrates of immune cell subsets. In conclusion, these data indicate expression on several lncRNAs in CAFs are associated with patient survival and are likely to play an important role in regulating CAF function.

The overexpression of lncRNA MEG3 inhibits cell viability and invasion and promotes apoptosis in ovarian cancer by sponging miR-205-5p

PURPOSE

Ovarian cancer is a common and fatal cancer in women. The long non-coding RNA (lncRNA) MEG3 was reported to affect the cellular processes of ovarian cancer, but the mechanisms remain unclear. Here, we aimed to explore the potential regulatory mechanism of MEG3 in ovarian cancer.

MATERIALS AND METHODS

A reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was conducted to analyze the expression levels of MEG3 and miR-205-5p in tissues and cell lines. An MTT assay was utilized to determine the cell viability of ovarian cancer SKOV-3 and OVCAR-8 cells. A flow cytometry analysis was employed to disclose the ovarian cancer cell apoptosis. The migration and invasion of SKOV-3 and OVCAR-8 cells were examined using a Transwell assay. A bioinformatics analysis indicated miR-205-5p as a direct target of MEG3, and a luciferase reporter assay was conducted to validate the interaction between MEG3 and miR-205-5p.

RESULTS

MEG3 was significantly down-regulated, while miR-205-5p was up-regulated in ovarian cancer tissues and cell lines. The overexpression of MEG3 and the knockdown of miR-205-5p inhibited cell viability, migration and invasion but promoted the apoptosis rate in ovarian cancer cells. MiR-205-5p was identified as a downstream gene of MEG3 and is negatively regulated by MEG3. The introduction of miR-205-5p reversed the up-regulation of MEG3-mediated suppression effects on cell viability, migration and invasion and increased cell apoptosis in ovarian cancer cells.

CONCLUSION

The overexpression of lncRNA MEG3 inhibits cell proliferation and cell invasion and promotes apoptosis in ovarian cancer by sponging miR-205-5p.

Long Non-coding RNA MEG3 Activated by Vitamin D Suppresses Glycolysis in Colorectal Cancer via Promoting c-Myc Degradation

Colorectal cancer (CRC), a common tumor, is characterized by a high mortality rate. Long non-coding RNA maternally expressed gene 3 (MEG3) serves a regulatory role in the carcinogenesis and progression of several types of cancer; however, its role in CRC remains largely unknown. The aim of this study was to explore the regulatory role and mechanism(s) of MEG3 in CRC. The Warburg effect or aerobic glycolysis is characteristic of the metabolism of tumor cells. To determine the effect of MEG3 on glycolysis of CRC cells, we used an XF analyzer to perform glycolysis stress test assays and found that overexpression of MEG3 significantly inhibited glycolysis, glycolytic capacity, as well as lactate production in CRC cells, whereas knockdown of MEG3 produced the opposite effect. Mechanistically, overexpression of MEG3 induced ubiquitin-dependent degradation of c-Myc and inhibited c-Myc target genes involved in the glycolysis pathway such as lactate dehydrogenase A, pyruvate kinase muscle 2, and hexokinase 2. Moreover, we found that MEG3 can be activated by vitamin D and vitamin D receptor (VDR). Clinical data demonstrated that MEG3 was positively associated with serum vitamin D concentrations in patients with CRC. We found that 1,25(OH)₂D₃ treatment increased MEG3 expression, and knockdown of VDR abolished the effect of MEG3 on glycolysis. These results indicate that vitamin D-activated MEG3 suppresses aerobic glycolysis in CRC cells via degradation of c-Myc. Thus, vitamin D may have therapeutic value in the treatment of CRC.

Meg3 Induces EMT and Invasion of Glioma Cells via Autophagy

Background

Glioma is one of the most common malignant tumors. Glioblastoma (grade IV) is considered the most malignant form of human brain tumors. Maternal expression gene 3 (Meg3) encodes a non-coding RNA (ncRNA) that plays an important role in the development and progression of cancer. However, the role of Meg3 in glioma cells remains largely unclear.

Methods

Reverse transcription-quantitative (RT-q) PCR was conducted to evaluate the mRNA expression related to cell autophagy and EMT while protein expression was detected by Western blotting. Staining of acidic vacuoles and immunofluorescence staining were used to detect autophagy. The ability of cells to migrate and invade was detected by Transwell migration and invasion assays.

Results

In the present study, it was found that the overexpression of Meg3 induced EMT, migration and invasion of glioma cells, whereas Meg3 overexpression induced autophagy of glioma cells. More importantly, the inhibition of autophagy impaired the EMT of glioma cells. In addition, Meg3-induced EMT, migration and invasion could be partially reversed by autophagy inhibitors, chloroquine (CQ) and Lys05, in glioma cells.

Conclusion

All data suggest that Meg3 induces EMT and invasion of glioma cells via autophagy. Overall, the findings of the present study demonstrate the importance of Meg3 in the molecular etiology of glioma, which also indicate its potential applications in the treatment of glioma.

CASC11 Overexpression Predicts Poor Prognosis and Regulates Cell Proliferation and Apoptosis in Ovarian Carcinoma

Introduction

It is known that CASC11 can promote colorectal cancer. However, the function of CASC11 in ovarian carcinoma (OC) remains elusive.

Methods

In this study, we measured the expression levels of CASC11 and miR-182 in both OC and healthy control samples by performing qPCR. The interaction between CASC11 and miR-182 was analyzed by the overexpression experiment and qPCR. Cell apoptosis was analyzed by cell apoptosis assay, and the prognostic value of CASC11 for OC was analyzed by survival curve analysis.

Results

We found that CASC11 and microRNA-182 (miRNA-182) were upregulated in OC. Plasma CASC11 was upregulated in OC patients and predicted early-stage OC. Follow-up study revealed that high plasma levels of CASC11 were closely correlated with poor survival conditions of OC patients. CASC11 and miRNA-182 were positively correlated in OC. Overexpression of CASC11 mediated the upregulation of miRNA-182 in cells of OC cell lines, while miRNA-182 overexpression did not significantly affect CASC11 expression. Overexpression of CASC11 and miRNA-182 promoted cancer cell proliferation and inhibited cancer cell apoptosis.

Conclusion

Therefore, CASC11 overexpression predicts poor prognosis and CASC11 regulates cell proliferation and apoptosis as well as microRNA-182 expression in ovarian carcinoma.

The Communication Between the PI3K/AKT/mTOR Pathway and Y-box Binding Protein-1 in Gynecological Cancer

Studies of the mechanistic (mammalian) target of rapamycin inhibitors (mTOR) represent a step towards the targeted treatment of gynecological cancers. It has been shown that women with increased levels of mTOR signaling pathway targets have worse prognosis compared to women with normal mTOR levels. Yet, targeting mTOR alone has led to unsatisfactory outcomes in gynecological cancer. The aim of our review was therefore to provide an overview of the most recent clinical results and basic findings on the interplay of mTOR signaling and cold shock proteins in gynecological malignancies. Due to their oncogenic activity, there are promising data showing that mTOR and Y-box-protein 1 (YB-1) dual targeting improves the inhibition of carcinogenic activity. Although several components differentially expressed in patients with ovarian, endometrial, and cervical cancer of the mTOR were identified, there are only a few investigated downstream actors in gynecological cancer connecting them with YB-1. Our analysis shows that YB-1 is an important player impacting AKT as well as the downstream actors interacting with mTOR such as epidermal growth factor receptor (EGFR), Snail or E-cadherin.

Molecular Mechanisms of Autophagy Regulation in Plants and Their Applications in Agriculture

Autophagy is a highly conserved cellular process for the degradation and recycling of unnecessary cytoplasmic components in eukaryotes. Various studies have shown that autophagy plays a crucial role in plant growth, productivity, and survival. The extensive functions of plant autophagy have been revealed in numerous frontier studies, particularly those regarding growth adjustment, stress tolerance, the identification of related genes, and the involvement of metabolic pathways. However, elucidation of the molecular regulation of plant autophagy, particularly the upstream signaling elements, is still lagging. In this review, we summarize recent progress in research on the molecular mechanisms of autophagy regulation, including the roles of protein kinases, phytohormones, second messengers, and transcriptional and epigenetic control, as well as the relationship between autophagy and the 26S proteasome in model plants and crop species. We also discuss future research directions for the potential application of autophagy in agriculture.

Association analyses of a genetic variant in long non-coding RNA MEG3 with breast cancer susceptibility and serum MEG3 expression level in the Egyptian population

BACKGROUND

LncRNA MEG3 rs7158663 has been shown to confer cancer susceptibility, maybe through altering its gene expression level.

OBJECTIVE

We aimed to weigh the effect of rs7158663 on MEG3 serum level and breast cancer susceptibility.

METHODS

We genotyped rs7158663 G > A and measured serum MEG3 in 150 breast cancer, 95 fibroadenoma , and 154 controls by the TaqMan method.

RESULTS

The presence of rs7158663 G > A is a risk factor for breast cancer among fibroadenoma patients and controls, AA vs. GG genotypes (OR = 6.320, 95% CI = 2.587-15.439, P< 0.0001 when compared to controls and OR = 10.825, 95% CI = 1.929-60.742, P= 0.007 when compared to fibroadenoma). Decreased serum MEG3 was observed in breast cancer group when compared with fibroadenoma and/or controls [median (IQR) = 0.43 (0.27-0.55)] (P< 0.0001). However, increased serum MEG3 was noted in fibroadenoma group when compared with controls (P< 0.0001). A significance decreased serum MEG3 was found to be associated with mutant A allele than with wild G allele (P< 0.0001). The results showed that rs7158663 and lower MEG3 were significantly associated with patients with higher TNM staging and larger tumor size > 5 cm.

CONCLUSION

The presence of both rs7158663 and low MEG3 are diagnostic and unfavorable prognostic factors for BC patients.

mi-R4435-2HG promotes proliferation and inhibits apoptosis of cancer cells in ovarian carcinoma by upregulating ROCK2

The present study aimed to investigate the involvement of long noncoding RNA mi-R4435-2HG in ovarian carcinoma. mi-R4435-2HG and Rho-associated protein kinase 2 (ROCK2) were demonstrated to both be upregulated in ovarian carcinoma. mi-R4435-2HG and ROCK2 were positively correlated in both tumor and healthy tissues. mi-R4435-2HG overexpression mediated the upregulation of ROCK2, while upregulation of ROCK2 did not affect mi-R4435-2HG. Overexpression of mi-R4435-2HG and ROCK2 led to promoted proliferation and inhibited apoptosis of cancer cells, while mi-R4435-2HG and ROCK2 knockdown had the opposite effect. In addition, ROCK2 knockdown attenuated the effects of mi-R4435-2HG overexpression on cancer cell proliferation and apoptosis. Therefore, mi-R4435-2HG promotes proliferation and inhibits apoptosis of cancer cells in ovarian carcinoma by upregulating ROCK2.

ATG3, a Target of miR-431-5p, Promotes Proliferation and Invasion of Colon Cancer via Promoting Autophagy

Background

Studies have indicated that ATG3 could mediate the effects of other tumor-related regulators in carcinogenesis. However, the expression, role, and mechanism of ATG3 itself in cancers are rarely revealed. Thus, we explored the expression, function, and mechanism of ATG3 in colon cancer.

Materials and methods

The expression of ATG3 was detected in colon cancer tissues and cell lines, as well as in adjacent tumor tissues and normal colon epithelial cells. The effects of ATG3 alteration on proliferation and invasion were further analyzed. The expression and role of miR-431-5p, a potential negative regulator of ATG3, were also studied. Eventually, the role of autophagy in ATG3 related effects in colon cancer was checked.

Results

ATG3 is upregulated in colon cancer tissues and cells demonstrated by qPCR and IHC. ATG3 knockdown significantly suppressed proliferation and invasion of colon cancer cells indicated by plate clone formation and Transwell invasion assays. The expression of miR-431-5p is downregulated and negatively correlates with ATG3 in colon cancer. Furthermore, luciferase report system, plate clone formation and Transwell invasion assays demonstrated that miR-431-5p could prohibit cell proliferation and invasion via directly targeting ATG3 in colon cancer. Eventually, Western blot, plate clone formation and Transwell invasion assays proved that autophagy block could antagonize the promotive functions of ATG3 on proliferation and invasion in cancer suggesting autophagy activation accounts for the promotive role of ATG3 on proliferation and invasion in colon cancer.

Conclusion

Collectively, ATG3 upregulation, caused by downregulated miR-435-5p, promotes proliferation and invasion via an autophagy-dependent manner in colon cancer suggesting that miR-431-5p/ATG3/autophagy may be a potential therapeutic target in colon cancer.

LncRNAs as Regulators of Autophagy and Drug Resistance in Colorectal Cancer

Colorectal cancer (CRC) is a common malignancy with 1. 8 million cases in 2018. Autophagy helps to maintain an adequate cancer microenvironment in order to provide nutritional supplement under adverse conditions such as starvation and hypoxia. Additionally, most of the cases of CRC are unresponsive to chemotherapy, representing a significant challenge for cancer therapy. Recently, autophagy induced by therapy has been shown as a unique mechanism of resistance to anticancer drugs. In this regard, long non-coding RNAs (lncRNAs) analysis are important for cancer detection, progression, diagnosis, therapy response, and prognostic values. With increasing development of quantitative detection techniques, lncRNAs derived from patients' non-invasive samples (i.e., blood, stools, and urine) has become into a novel approach in precision oncology. Tumorspecific GAS5, HOTAIR, H19, and MALAT are novels CRC related lncRNAs detected in patients. Nonetheless, the effect and mechanism of lncRNAs in cancer autophagy and chemoresistance have not been extensively characterized. Chemoresistance and autophagy are relevant for cancer treatment and lncRNAs play a pivotal role in resistance acquisition for several drugs. LncRNAs such as HAGLROS, KCNQ1OT1, and H19 are examples of lncRNAs related to chemoresistance leaded by autophagy. Finally, clinical implications of lncRNAs in CRC are relevant, since they have been associated with tumor differentiation, tumor size, histological grade, histological types, Dukes staging, degree of differentiation, lymph node metastasis, distant metastasis, recurrent free survival, and overall survival (OS).